The support of overhead lighting systems in the environment of a theater stage is usually accomplished by mounting the light fixtures and other fixtures to an elongated horizontally oriented support beam. Usually, the light support beam can be lowered from above the stage down to the level where the technician can mount, adjust, replace, or otherwise maintain the lights and other fixtures. The support beam can then be raised to the desired elevated position for use in the stage production. Typically, the horizontal support beam is suspended at its ends by ropes or cables. In the older light supports the cables extended from the support beams upwardly to pulleys that were attached to the overhead structure of the building. In most cases, counterweights were attached to the cables to balance the load and the cables were controlled by a motor operated winch that is remotely positioned at the stage level. In many instances, the number of winches, cables, pulleys and other devices necessary to raise and lower the several light support beams was expensive and sometimes confusing to the technician, requiring the winches for each cable to be at the stage level, requiring a riser segment of the cable to extend upwardly from the stage to the overhead pulley, and then downwardly to the light support beam.
Another problem with the older stage light supports was that the pulleys that are attached to the overhead structure of the building are remote from the technician and from the operator, making inspection and replacement of the pulleys difficult. Yet another problem is the hazard of the sometimes heavy overhead equipment mounted on the stage light supports, and possibly overstressing the cables, pulleys, winches, or motors that are used to raise and lower the stage light supports. In some cases, these elements are positioned in remote locations, making it difficult for inspection, maintenance, repair, and replacement.
Later, stage light supports were constructed with motors and winches mounted directly to the light support, with each support cable requiring only one riser cable segment to extend from the ends of the light support to the overhead support structure. This eliminated the requirement for pulleys attached to the overhead structure and the segments of the riser cables that had to extend from the overhead pulleys down to the stage level and the previously required counterweights, etc. However, the newer light supports still had to include brakes for the cables to hold the light support in a fixed position, and the winch drums and brakes added weight to the assembly.
It would be desirable to provide a stage light support that has substantially all of its moving parts in one location, preferably on the stage light support itself, so that when the stage light support is lowered to stage level, its moving components can be inspected, maintained, etc. And, it would be desirable that the stage light support not be required to carry its own brakes and that a linear cable drive be employed for its cables to avoid the use of winches and their cable drums. It is to these features that this invention is directed.